Fluid pump



July 15, 1958 R. B. KNowLEs 2,843,046

677' rae/wry.

R. B. KNowLEs July 15,A 1958 FLUID PUMP 2 Sheets-Sheet 2 Filed Feb. 16. 1956 United States FLUID PUMP Robert B. Knowles, Maywood, Caii.

Application February 16, 1956, Serial No. 566,040

Claims. (Cl. 1035-46) This invention relates to a Huid pump and more particularly to a fluid pump automatically operable in a subsurface position by circulation of pressure fluid supplied from above surface to the pump. The iluid pump of this invention is useful in oil wells but may be used in other industrial installations for raising liquids.

The present invention is an improvement of the hydraulic pump described and claimed in my United States Letters Patent No. 2,544,094, issued March 6, 1951.

Usually sub-surface pumps for raising iluids such as oil in a well employ a long string of sucker rods reciprocally movable to operate the sub-surface pump. Such a string of sucker rods require relatively heavy, cumbersome actuating machinery on the surface and are of low mechanical efciency. Such strings of sucker rods are subject to wear, breakage and stretch considerably during the lifting stroke.

The fluid pump of this invention does not employ sucker rods and includes a piston means movably positioned in a production casing which extends into a well hole. A string of pressure tubing within the production casing provides means for supplying uid under pressure to the piston means and automatic discharge means for the pressure liuid on opposite sides of the piston means are alternately operable so as to cause the piston means and an associated pump plunger to reciprocally move within the production casing.

Some of the advantages of the present invention are that the construction is simple and efficient, there are few movable parts and the uid pump cannot assume a deadzcenter position from which it cannot be moved by application of fluid pressure.

The primary object of this invention is to disclose and provide a fluid pump which improves the construction and automatic operation ofthe pump described in my United States Letters Patent No. 2,544,094.

An object of this invention is to disclose and provide such a fluid pump wherein means are provided for dampening movement of Vthe piston means at each end of its Istrokevin the production casing.

Another object of this invention is to disclose and pro'-V vide Va novel piston construction of the type useable in a uid pump wherein the piston is provided with means for' controlling the rate of` movement thereof in one direction.

More particularly, the present invention is directed to a novel arrangement of axiallyspaced valve means carried by the piston construction, said valve means being operable by a relatively free iioating shuttle rod extending therebetween whereby in one positie-n of the push rod one valve is seated and the other valve is unseated.

Fig. 1 is a longitudinal sectional view taken in a plane bisecting a uid pump embodying this invention and located in a well hole, the pump parts being positioned to begin a downstroke of the piston means.

Fig. 2 is an enlarged sectional view of a portion of the 2,843,045 Patented July 15, 19,58

uid pump shown in Fig. 1, the section being taken in the plane indicated by line II-II of Fig. 1.

Fig. 3 is a transverse sectional view taken in the plane indicated by line lll-III of Fig. l.

Fig. 4 is a transverse sectional view taken in the plane indicated by line IV-IV of Fig. l.

Fig. 5 is a sectional view taken in a vertical plane bisecting the well hole showing the fluid pump at the end of a stroke, the pump parts being in Aposition to begin an upstroke of the piston means.

Fig. 6 is a fragmentary sectional view taken in the planes indicated by line VI-Vl of Fig. 3.

Fig. 7 is a transverse sectional view taken in the plane indicated by line VII-VII of Fig. 6.

In Fig. l a fluid pump means embodying this invention is generally indicated at 10. The pump means 10 is positioned within a production casing 11, the production casing 11 being lowered and positioned within a stationary outer casing 12 provided with a plurality of perforations 13 at a production Zone or formation.

The production casing 11 carries at its bottom end a suitable shoe 14 which supports a working barrel 15. The bottom end of barrel 15 is provided with a valved inlet port 16 for flow of well fluid into the barrel 15. A bali valve 17 is provided with a valve seat on the inner end surface of working barrel 15 to close port 16. The upper end of the production casing 11 extends above the surface of the ground. Spaced above shoe 14 a predetermined distance, a spider 2li, having a plurality of openings 21 therein, may be secured in any suitable marmer as by welding. A ring valve member 22 seats on the spider 20 above openings 21 and serves as a check valve for said openings and to support a column of iuid above spider 20 during pumping operations. The spider 20 is also secured at its inner circumference to the lower end of a string of pressure tubing 23 which extends above the surface of the ground and is connected to a suitable source of pressure uid in well known manner.

Slidably movable within the production casing 11, between shoe 14 and spider 20, is piston means 25 comprising an upper portion 26 threadedly connected as at 27 to a lower portion 28. The lower portion 28 includes a downwardly extending section 29 reduced in cross section along one diameter to provide flat faces 30 (Fig. 2). The depending section 29 supports a plunger rod 31 through a longitudinally slotted boredl member 32 threaded as at 33 to depending section 30, the lower end being threaded as at 34 to the top end of the pump rod 31. The pump rod 31 carries a bottom plunger 35 provided with a pair of circumferential seal rings 36 for slidable sealing engagement with working barrel 15. Plunger 35 is axially ported at 37 and is provided with valve means including a ball valve 38 and a valve seat 39.

Above valve seat 39, rod 31 is longitudinally slotted at d@ for liow of fluid from working barrel 15 Vto a bottom uid chamber 41 provided between shoe 14 and the bottom of piston means 25.

The upper portion 26 of piston means 25 includes an upwardly directed extension 44 threadedly connected as at 45 to a hollow tubular member 46 which is threadedly connected at 47 to a top plunger 48 slidable in pressure tubing 23, said plunger being provided with a pair of circumferential seal rings 49. Plunger 48 is provided with a through bore and a top valve seat 50 for a top ball valve 51 of top valvemeans carried by the uid pump. The ball valve 51 is held in association with plunger 48 by a cage 52 formed on the top of plunger 48.

The lower portion 2S of piston means 25 includes a bottom axial valve chamber 54 within which is provided a bottom ball valve 55. The ball valve 55 in upper position is adapted to seat on a valve seat 56 and in lower said passageways 58 opening at their top ends into the hollow tubular member 46 and opening at their bottom ends into axial chamber 54. Passageways 58 conduct pressure iluid pumped through pressure tubing 23 to chamber 54 to move the piston means upwardly as later described. Mating annular grooves 59 in meeting faces of upper and lower portions of the piston means facilitates connection ofupper and lower portions of passageways 58.

Ports 60 in depending section 29 afford iluid communication between bottom iluid chamber 41 below piston means 25 :and valve chamber 54.

A second passageway means 62 provi-ded in th-e upper and lower portions Vof the piston means leads from valve chamber 54 axially upwardly and discharges through a pair of diverging portions 63 into upper fluid chamber 64 between piston means 25 and the spider 29. The entrance to passageawy means 62 is provided with the valve seat 56 for the ball valve 55.

Means to cushion the upstroke and the downstroke of the piston means 25 are provided at opposite ends thereof. The upper portion 26 of pist-on means 25 is provided with a bypass 66 (Fig. 7) leading from one of the passageways 58 and terminating in an enlarged recess 67. A bypass port 68 communicates with said recess 67 and upper fluid chamber 64. Bypass 66 and bypass port 68 are provided with a valve means including a ball element 69 biased upwardly into valve seated position by a spring 70 within recess 67. The top surface of ball 69 may'contact a reduced bottom end portion 71 of an upwardly extending striker rod 72 which is slidably positioned in a longitudinally extending bore 73 in upper portion 26 of the piston means. The striker rod 72 may be provided with a ilat cut out portion 74- which may engage a retainer pin 75 for holding the striker rod 72 in association with the piston means. The length of striker rod 72 is preselected so that upon contact of its upper end with spider as at 76 the piston means is almost at the end of its upstroke. Contact of striker rod 72 with spider 2) at the end of the upstroke serves to open valve 69 by depressing said ball element 69 against spring 70 and to thereby admit a limited amount of pressure fluid from passageway 58 into the chamber 64 and thus limitedly cushion upward movement of the piston means.

The piston means 25 may be cushioned on its downstroke by a compression coil spring 78 seated on top of shoe 14 and encircling plunger rod 31. Compression spring 78 is of selected length and on the downstroke of the piston means the top end of coil spring 78 will first contact a transversely extending member 79 slidable in a longitudinal slot 80 provided in member 32. The lowersection 29 may be provided with an aligned transversely extending groove 81 to receive member 79 when the pump plunger is at approximately the bottom end of its stro-ke Whereat the coil spring may be under compression and member 79 seated against section 32 in groove 81.

Control of the rate of travel of the piston means, in addition to control provided by pressure fluid, may be provided by a selected orifice element 82 tted in one diverging passageway portion 63 (Fig. 2) to restrict flow of well uid between uid chamber 64 and valve chamber 54.

Means to actuate bottom ball valve 55 and the tcp valve means, including ball valve 51, includes an upwardly directed push rod 83 carried by transverse member 79 andv which extends through an axial bore 84 provided in the top end of member 32. From a consideration of Fig. 5, it will be apparent that when the 'd piston means 25 is at the end of its bottom stroke, the top of push rod 83 has pushed ball valve 55 against its seat 56 to close passageway 62. In contact with the top of ball valve 55 is a free lloating axially disposed shuttle rod86, said shuttle rod 86 extending upwardly through passageway 62 and through a bore 37 provided with packing 88 and into the hollow tubular member 46. At its top end, shuttle rod 8.6 contacts the bottom portion of ball valve 51 which is retained within cage 52.

When the piston means 25 is at the top end of its stroke, the ball valve 51 is adapted to be contacted by a downwardly biased valve pin 90 carried by a ported spider 91 secured to pressure tubing 23 a selected distance above the lower end thereof. The pin 90 carries a fixed collar 92 and a coil spring 93 is compressed between collar 92 and spider 91. At the top of the stroke of piston means 25, the lower end of pin 90 projects through an opening 94 in the top of cage 52 to contact the top portion of ball valve 51.

Operation of the fluid pump may be best described by reference to Figs. 1 and 5. In Fig. 1, the piston means is shown at the top of its stroke and just prior to commencement of the downstroke. Pressure uid flowing downwardly through the pressure tubing 23 acts upon the ball valve 51 and the top end of plunger 48 to cause the piston means to move downwardly, the valve member 51 being seated on its valve seat 50. During downward movement of the piston means 2S, top Huid chamber 64 expands and check valve 22 is seated in order to retain a `column of well fluid thereabove within the production casing. With the ball valve 51 in seated position, the shuttle rod 86 has pushed the ball valve 55 into lowermost position so that passageway 62 is open to admit fluid to chamber 64 from lower fluid chamber 41. Well uid in the working barrel 15 on downward movement of the pump plunger is urged upwardly through valve port 37 into the lower chamber 41. Valve 17 is closed during downward movement of the piston means 25 and pump plunger.

When the transverse member 79 contacts the top of coil spring 78, its downward movement is stopped and relative movement between the rod 83 and the lower end of the piston means 25 causes rod 83 to move upwardly into valve chamber 54 and into contact with the ball valve When the piston means reaches the bottom extremity of its stroke, the rod 83 has pushed the ball valve 55 into seated position and in so doing has thrust the shuttle rod 86 upwardly relative to the piston means so as to unseat the top ball valve 51. Unseating of the ball valve 51 permits pressure uid to ow downwardly through the hollow tubular member 46 into the two passageways 58 and thence into the axial valve chamber 54. Since ball valve 55 is located above the inlet ends of passageways 58 into valve chamber 54, the pressure fluid holds ball valve 5S in seated position while the piston means travels upwardly. Fig. 5 illustrates the position of the ball valves 51 and 55 at the bottom of the downstroke of the piston means.

In this condition of the pump means, pressure exerted by the pressure fluid is transmitted through the passageways 60 into bottom uid chamber 41 and commences to act against the bottom portion of the piston means to cause the piston means to move upwardly. As the piston means moves upwardly, the expanded upper uid chamber 64 is provided communication with the annular spaced above spider 20 because pressure of fluid in chamber 64 lifts check valve 22. As the piston means travels upwardly, the pump plunger draws welll uid into the working barrel.

As the piston meanscontinues upwardly, close to the end of its upstroke the top end of striker rod 72 contacts spider 20 so as to admit a limited amount of pressure uid through the bypass passageways 66 and 68 into the upper chamber to cushion the upward movement of the piston means. At approximately the same time, the cage on the top plunger has admitted pin 90 into bore 94.for

93 is compressed and just as the spring 93 becomes solid,

the piston means reaches the top end of its upstroke.

When spring 93 becomes solid, pin 90 acts as a fixed pin and presses downwardly upon ball valve 51 to urge ball valve 51, shuttle rod 86, and ball valve 55 downwardly 'against the pressure fluid in the chamber 54. As soon as ball valve 51 is seated on its valve seat 50, flow of pressure fluid is stopped to valve chamber 54 and passageway 62 is open to admit well fluid in bottom chamber 41 into the upper chamber 64 and the downstroke of the piston means commences again. This cycle is automatically repeated, well fluid being lifted through the piston means and into the production casing above the spider 20.

lt will thus be readily apparent to those skilled in the art that reciprocal movement of the piston means caused by flow of pressure fluid displaces well fluid from the bottom fluid chamber 41 through the piston means into the upper fluid chamber 64 and then above the spider 20 Where a column of well fluid is collected and lifted to the surface. The piston means is automatically operable by the particular arrangement of the top ball valve 51 and the ball valve 55 with the shuttle rod 86 extending therebetween. Pumping operations may be commenced regardless of the position in its path of travel at which the piston means stopped in a prior pumping operation .and thus there is no inoperative dead center position of the piston means. It will be noted that the rate of travel of the piston means is positively controlled by orifice element 82 and by pressure fluid introduced through the pressure tubing. In addition, the travel of the piston means is cushioned at each end, one end having a cushioning spring and the other end being provided with means for admitting a limited amount of pressure fluid just prior to the end of the upstroke of the piston means.

It will be evident that an efficient fluid pump has been provided which is of simplified construction, inexpensive to manufacture, and positive and foolproof in operation. The employment of ball valves together with a free floating shuttling rod to coordinate action of the ball valves produces an efficient arrangement which does not require frequent repairs.

It will be understood by those skilled in the art that various modifications and changes may be made in the fluid pump described above and which come within the spirit of this invention and all such changes and modifications coming within the scope of the appended claims are embraced thereby.

I claim:

l. In a fluid actuated pump for a well including a pressure tubing within a production casing and terminating Vin spaced relation to the end of the production casing,

said production casing being provided with a working barrel at its lower end, the combination of: a piston means slidable in the production casing between the end of the pressure tubing and the working barrel and provided with a top plunger slidable in the pressure tubing, and a bottom plunger slidable in the working barrel; said top plunger being provided with top ball valve means, said piston means having a valve chamber adjacent the bottom thereof; said piston means having a plurality of passageway means providing communication between said valve chamber and the production casing below said piston means, said valve chamber and the production casing above said valve chamber, and said valve chamber and said pressure tubing above said top plunger; ball valve means in said valve chamber for selectively closing the passageway means between said valve chamber and the production casing above said valve chamber; and a free floating valve actuating shuttle rod extending through the passageway means between the valve chamber and said pressure tubing and engageable with said ball valve means in said valve chamber and said top ball valve means in said top plunger for opening one of said ball Valve means while the other is closed.

2. In a fluid pump'as stated in claim l including means carried by the piston means for admitting pressure fluid from one of said passageway means into the production casing above the-piston means at a preselected point in upward path of travel of said piston means.

3. A fluid pump as stated in claim 2 wherein said means to admit pressure fluid includes an upstanding rod to engage said pressure tubing when said piston means is at a selected distance therefrom, said rod being upwardly biased, a valve element in contact with said rod for unseating said valve element upon engagement of said rod with said pressure tubing, said valve element controlling passage of pressure fluid through a bypass provided in said piston means.

4. In a fluid pump as stated in claim l wherein cushioning means including a coil spring is provided between said working barrel and the bottom end of the piston means.

5. In a uid. pump as stated in claim l wherein means are provided in said pressure tubing for limiting upward movement of the piston means and for causing said spaced valve means and floating shuttle rod extending therebetween to simultaneously move in one direction.

6. In a fluid pump adapted for use in a production pipe between means defining a working space in said pipe and including a pressure tubing within said pipe, a piston means reciprocally movable in said working space and including a valve chamber in said piston means, a plunger extending into the pressure tubing, said piston means being provided with a plurality of passageways, including a pressure fluid passageway, in communication with said valve chamber, the provision of: a first ball valve in said valve chamber positionable above inlets of the pressure fluid passageway; a second ball valve associated with said plunger and operably associated with said pressure fluid passageway; and means extending from said valve chamber through one of said passageway means in said piston means and through said pressure fluid passageway to said second ball valve for operative contact at each end with said first and second ball valves.

7. In a fluid pump adapted for use in production pipe between means defining a working space in said pipe and including a pressure tubing within said pipe, a piston means reciprocally movable in said working space and including a valve chamber in said piston means, a plunger extending into the pressure tubing, said piston means being provided with a plurality of passageways, including a pressure fluid passageway, in communication with said valve chamber, the provision of: a first ball valve in said valve chamber positionable above inlets of the pressure fluid passageway; a second ball valve associated with said plunger and operably associated with said pressure fluid passageway; and a floating shuttle rod extending through said piston'means and into said plunger and adapted to contact at opposite ends said first and second ball valves.

8. In a fluid pump adapted for use in a production pipe between means defining a working space in said pipe and including a pressure tubing within said pipe, a piston means reciprocally movable in said working space and including a valve chamber in said piston means, a plunger extending into the pressure tubing, said piston means being provided with a plurality of passageways, including a pressure fluid passageway, in communication with said valve chamber, the provision of a first ball valve in said valve chamber positionable above inlets of the pressure fluid passageway; a second ball valve associated with said plunger and operably associated with said pressure fluid passageway; a floating shuttle rod extending through said piston means and into said plunger for selective, operative contact with said first and second ball valves; and a valved bypass in said piston means interconnecting said pressure fluid passageway and the working space above the piston means.

9. In a fluid pump adapted for use in a production and including a pressure tubing within said pipe, a piston means reciprocally movable in said working space and including a valve chamber in said piston means, a plunger extending into the pressure tubing, said piston means being provided with a plurality of passageways, including a pressure fluid passageway, in communication with said valve chamber, the provision of z a rst ball valve in said valve chamber positionable above inlets of the pressure fluid passageway;` a second ball valve associated with said plunger and operably associated with said pressure fluid passageway; a valved bypass in saidpiston means; and means extending from said pistonl means and operably associated with said valved bypass to open said bypass to admit pressure uid into the space above the piston means.

10. In a uid pump adapted for use in a production pipe between means dening a working space in said pipe and including a pressure tubing within said pipe, a piston means reciprocally movable in said working space and including a valve chamber in said piston means, a plunger extending into the pressure tubing, said piston means being provided with a plurality of passageways, including a pressure fluid passageway, in communication with said valve chamber, the provision of: at first ball valve in said valve chamber positionable above inlets of the pressure uid passageway; a second ball valve associated with said plunger and operably associated with said pressure fluid passageway; and means in one of said passageways in said piston means other than the pressure fluid passageway to restrict ow of fluid therethrough to control rate of travel of the piston means.

References Cited in the file of this patent UNITED STATES PATENTS 2,261,752 Buckner Nov. 4, 1941 2,544,094 Knowles Mar. 6, 1951 

